If this was actually about a security risk, they would be doing this on all airlines, not just airlines originating from Muslim majority countries. If you take Royal Jordanian to a European hub, then hop on a US carrier, you'll be able to take your gear on board. So this does exactly what to mitigate a security risk?

It does however force business travelers to rethink flying Emirates, Etihad, etc and fly United, etc instead. I'll be interested to see if these airlines sue.